Lens latitude

[Joshua Csehak]

In the Jan 2010 issue of AC, Shane Hurlbut, ASC mentions that when he switched to Panavision Primo lenses (from still ones) for shooting on the Canon 5D mkII, he got an extra stop and a half of latitude on either end. That's 3 more stops total, just from the lens! (9 stops with still, 12 stops with Primo.)

 

How is that even possible? I always looked at lens differences in terms of sharpness, color reproduction, breathing, stuff like that; but I had no idea different lenses had different dynamic ranges. What are other people's experiences with this? Do you have go-to lenses for maximum dynamic range?

[Tom Jensen]

It's a little confusing. What he is really saying is that the lens was faster by a stop and a half. It doesn't really mater how far you can stop down. Nobody shoots at f:32. Most DP's shoot with the aperture more opened than closed. On interiors and night exteriors, you are limited with the amount of light you have or use. On day exteriors, you are trying to control depth of field. Too much depth is considered undesirable. Wide open is not always desirable either because it can be a focusing nightmare. The lens does not perform its' best wide open. It usually perform best two stops closed from wide open. Lens speed and quality is a factor of many things but cost, design, coating, glue, glass, size are just a few. We aren't re-invention the wheel with lenses so don't let Shane's terms throw you off. I also want to add that a lot of DP's know the stop where they want to shoot and light to that. The range of stops might be more but really the benefit was gaining a stop and a half. I haven't read the article yet. What still lenses was he using.

Edited January 14, 2010 by Tom Jensen

[Joshua Csehak]

He didn't say what still lenses he was using, but here's the line I'm referring to:

 

"Shooting with still lenses, I was seeing about 5 1/2 stops below key and 3 1/2 stops over. When we went to the Primos, the latitude increased by about 1 1/2 stops in both directions."

 

Am I missing something? How can that be taken any other way?

[Tom Jensen]

I'm a film guy. Don't know much about digital. In film 5 stops under is total black. 3.5 stops over you can still see texture in your whites which seems normal. I'm not sure what he's saying other than he can see a little more either through the lens or on the monitor.

[K Borowski]

Yeah, agreed. If he was referring to "latitude" it was in his ability to see or extra F/stops on either end, not in the actual latitude of the lens as it rendered on film.

 

The dynamic range of film is pretty set. An F/stop is just a hole that controls the amount of light that passes through the lens onto the film.

 

Sorry, nothing "magic" about a particular lens manufacturer and their product. Where lenses really compete against each other is in the sharpness, speed (the fastest F/stop/T-stop), and lack of breathing with zoom lenses.